1. Field of the Invention
The present invention relates to generally to inter-levels and more specifically to inter-levels with good resistance to the diffusion of a metallization therethrough.
2. Description of the Background Art
As circuit technology continues to advance, factors affecting the performance of the interconnect system become increasingly important. A larger portion of the total circuit delay will be caused by the resistance and capacitance of the interconnect system. To address these issues, copper, with its relatively low resistivity, and various polymers, with low dielectric constants and attractive processabilities, have been proposed. Of the many low dielectric constant polymers currently being studied, polyimides are the most mature with respect to processing and process integration. There are problems associated with polyimides such as moisture absorption which acts to increase the dielectric constant, dielectric anisotropy, and copper ion diffusion. Previous studies using SIMS (Secondary Ion Mass Spectroscopy) indicated copper to move rapidly throughout polyimide spin cast films. When copper diffuses as a singly charged positive ion through the dielectric the insulating capacitance is compromised. Another set of resin systems based on benzocyclobutenes have shown resistance to copper ion diffusion with relatively low dielectric constants. A need exists for even lower dielectric constant resins that can be used as inter-level insulators with copper metallization.